The objective of the research program proposed here is an optical periodontal probe tailored to automatically measure and record multiple tissue parameters deemed important for disease detection and treatment monitoring. As a first step in the development of a multi-functional device, a probe designed to mimic the visual measurements made by dental clinicians to determine pocket depth, bleeding on probing (BOP) and tissue coloration will be constructed. The BOP and tissue coloration measurement will serve as an indicator of present inflammatory activity, while the pocket depth measurement will be useful for longitudinal periodontal disease monitoring. The pocket depth measurement will be completed using a new scanning interferometric technique. Both BOP and tissue coloration will be determined using a straightforward optical spectroscopic technique. Phase I will verify that the envisioned optical probe can measure pocket depth with an accuracy of 0.25 mm and indicate BOP using a simulated in vivo model. Optical methods to determine other tissue parameters, including tissue coloration and sulcular pH, will be evaluated in Phase II. Clinical verification of the multi-purpose optical probe will also be completed in Phase II, when a compact, robust clinically useful prototype will be constructed.